1. Field of the Invention
This invention relates to a pneumatically controlled multiple valve system used by the semiconductor and microcircuit industries in the operation of certain rinser-dryer systems during the processing of semiconductor wafers. 2. Description of the Invention
Valves for transfer of fluids may be as simple or complicated as the task requires to meet a wide variety of pressure, temperature, flow and fluid requirements. In the semiconductor and microcircuit industries, where contaminants of molecular dimensions are of critical concern, the need for clean, reliable, precise, accurate and long lasting valves is self evident.
Current valves known to be used in the rinser-dryer equipment employed in semiconductor wafer manufacture generally are complicated in design, contain many parts made of a variety of metallic and non-metallic materials and often have a short operating life, due to failure of various components at various times. Also the closing operation of the valve often is abrupt, resulting in a "hammer" effect upon the fluid line leading into the valve. This places excessive and unnecessary strain on the valve and associated components and tends to promote valve failure.
Inspection of the current art and available commercial valves, such as the valve now used, and manufactured by Semi-Tool Corp. of Kalispell, Mont., indicates that a simple, reliable, durable valve as in the described invention, is highly desirable in operation of rinser/dryer equipment used in the semiconductor and microcircuit industries.